But Dr Obi is now facing the threat of legal action from a woman who says she paid him #3,500 after she appealed for help with a mystery sickness.

He wrote to Margaret Lewis, 58, after she placed an advert in the British Medical Journal asking for a doctor who could cure an undiagnosed 20-year illness.

Mrs Lewis claims she was visited twice by Obi but she has not been able to contact him since.

Dr Obi, using the title professor, said his company, Advanced Wellness Interventions, could provide "a multi-disciplinary team of almost seven different practitioners".

He said he would need a lifetime registration fee of #2,500, and an appraisal fee of #1,000 to cover a three-hour telephone consulting session and an intensive home visit and until this was paid in cash into his bank account he could enter into no further correspondence.

Desperate to be cured, Mrs Lewis, widowed and living alone, says she paid her life savings into Dr Obi's account as requested, and although he did visit her house she said he made no diagnosis, arranged no tests and has not been in touch since.

She said: "I don't normally part with money like this, but I was so desperate because I have been ill for so long and no one can do anything.

"He did come down and see me but directed a lot of the questions at my partner and we didn't seem to get anywhere.

"He was very charming. He kissed my hand on the way out.

"But that was the last I've heard from him. We've called and called all the numbers, even an international mailbox he gave us because he said he travelled in the tropics a lot.

"He promised me a cure, but now I have no money and will continue to get into more debt paying for carers for an illness no one can seem to diagnose. I am devastated."

The Chronicle tried to find Dr Obi at the address he gave Mrs Lewis but we found the house, in Aycliffe Crescent, Wrekenton, standing empty, having been repossessed by the building society.

Neighbours told us he told them he had gone on a cruise and would be away for a while but they were keen to speak to him because they say he had borrowed furniture from them and not returned it.

We traced Dr Obi to an upstairs flat in Mersey Place, Carr Hill. He has owned this property for several years but according to neighbours only recently moved back in full-time.

When we knocked on the door, Dr Obi refused to speak to us, shouting "no comment" several times.

We also left several messages on mobiles and land lines and e-mailed him asking him about Mrs Lewis and his businesses.

Dr Obi has made no comment on the allegations themselves but instead posted a message on one of his websites claiming to a victim of "a massive racist smear campaign" by "shameless media elements".

He has also made lewd and defamatory references to a Chronicle reporter on the same site.

Neighbours described Dr Obi as a "smooth talker" who was very well-educated and always on his computer. They said he had told them he was a locum doctor.

Obi was suspended by the GMC last January after being found guilty of serious professional misconduct while working at South Tyneside District Hospital between August 2000 and January 2001.

Among the allegations were that he failed to attend to patients, wrote inappropriate notes about colleagues and gave a dating agency phone number to a psychiatric patient.

Dr Obi has not re-applied for registration to the GMC.

A spokeswoman for the GMC said: "You don't have to be registered to offer medical advice but if somebody is passing themselves off as a doctor then it is a matter for the police."

Dr Obi uses a number of medical and professional titles online and claims membership of a long list of organisations.

These include FRCAM (Dublin), FRIPH (UK) FACAM (USA) and provost of the Royal College of Alternative Medicine (RCAM Dublin).

The Royal College of Alternative Medicine appears to be little more than a website. It is listed as a company at Companies Registration Office in Dublin but the phone number given is not in use. Fellowship of the RCA is available to buy from the site.

Dr Obi, originally from Nigeria, does not say where he did his doctorate in science (DSc) or when he joined the Royal Institute of Public Health (RIPH). No one was able to confirm whether or not Dr Obi was a member of the RIPH when the Chronicle contacted it.

Dr Obi says he is a member of the Institute of Clinical Research (ICR), a training body based in Maidenhead that sells membership online for #50.

He also says he is a member of the International Stress Management Association, which also sells membership online from as little as #30.

Dr Obi also claims to be a member of the World Medical Association (WMA), which sells annual membership via its website for 37 euros.

August 2000 - Starts work as a senior house officer in the department of psychiatry at South Tyneside District Hospital.

January 2001 - Leaves following a complaint.

September 2002 - Registration suspended by the GMC for 18 months for reasons

surrounding his "fitness to practise" and "for the protection of the public".

January 2003 - Dr Obi is found guilty of serious professional misconduct by a GMC hearing which he does not attend.

Obi is said to have made offensive and insensitive comments to psychiatric patients and failed to respond to his pager.

In a previous job in Harrogate it was alleged he failed to conduct an outpatient clinic and failed to properly treat a patient with a heart attack.

And in Pontefract he is said to have described a colleague as a "stupid cow", spent an excessive time on a computer, and called a surgeon a liar.

August 2003 -Dr Obi launches a campaign to get elected to the North East Assembly, even though no referendum has been held. He describes himself as "North East Assembly Aspirant - Independent (non-aligned)".

August 2004 -Dr Obi refused to speak to the Chronicle. His campaign website is closed down after he posted defamatory statements there.